#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<stack>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=1e3+100;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
LL a[maxn];
vector<LL>ans;
void pri(){
     for(LL i=0;i<ans.size()-1;i++){
        cout<<ans[i]<<".";
     }
     cout<<ans[ans.size()-1]<<"\n";
}
int main(void){
   	cin.tie(0);std::ios::sync_with_stdio(false);
    LL t;cin>>t;
    while(t--){
        ans.clear();
        LL n;cin>>n;
        for(LL i=1;i<=n;i++) cin>>a[i];
        ans.push_back(1);
        pri();
        for(LL i=2;i<=n;i++){
            if(a[i]==1){
                ans.push_back(a[i]);
            }
            else{
                if(!ans.empty()&&a[i]-1==ans.back()){
                    ans.pop_back();
                    ans.push_back(a[i]);
                }
                else{
                    while(!ans.empty()&&a[i]-1!=ans.back()){
                          ans.pop_back();
                    }
                    if(!ans.empty()) ans.pop_back();
                    ans.push_back(a[i]);
                }
            }
            pri();
        }
    }
   	return 0;
}
